Centrifugal pump



Patented Dec. 30, 1924.

UNTED S CENTRIFUGAL PUMP.

Application filed April 12, 1923. Serial Np. 631,586.

ToaZZ whom t may concern.'

Be it known that we, TAD DANroRD and ALBION l?. CURTIS, citizens of the United States, residing at Granby, in the county of Grand and State of Colorado, have invented certain new and useful Improvements in Centrifuga-l Pumps, of which the following is a specification.

The invention resides in the provision of certain new and useful improvements in centrifugal pump structure wherein the working principle is truly centrifugal, and whereby a given amount of water may be pumped with less power than is usually required.

The invention has for its object to pro-A vide a simple, compact and inexpensive design of centrifugal pump structure wherein the impeller is in the nature of a rotating casing which generates pressure within its own confines, and which is so designed as to effect the desired pumping action at a minimum expenditure of power and in a manner whereby the pumped fluid is forced out into the main casing and discharged therefrom wholly through the centrifugal action of the fluid within the impeller and without any driving action by the outside surface of the impeller whatever. With the above and other objects in view that will hereinafter appear, the invention resides in those novel details of construction, combination and larrangement of parts, all of which will be first fully described, then be specifically pointed out in the appended claims, and illustrated in the accompanying drawings, in which:

Figure 1 is a central vertical cross section of our improved pump taken across the line of division of the main pump casing.

Figure 2 is a horizontal section and part plan view, taken substantially on the line 2--2 of Figure 1.

lVhile we have illustrated our invention as applied to a pump in which the impeller rotates on a horizontal plane, it is to be understood that the same is applicable to pumps in which the plane of rotation is vertical as well.

ln the drawings, in which like numerals of reference indicate like parts in all of the figures, the invention is shown as including a main casing comprising half sections 1 and 2 which are secured to each other in cooperative relation, as at 3, to form a fluid chamber 4 therebetween, and in order to make the said casing fluid-tight, we provide any suitable gasket 5. Thecasing sections 1 and 2 cooperate tol provide an impeller hub bearing 6 and an `impeller shaft bearing boss 7 the latter being provided with a suitable gland 8, as shown. The said half sections 1 and 2 are further provided with downwardly projecting extensions whereby a connecting union iiange 9 is provided, and the said casing sections are also provided with half apertures which cooperate in forming outlet ports 10 arranged as shown, and discharging pipes 11 are secured in cooperative relation with the said ports 10, as at 12.

Thus far it will be seen that we have provided a pump casing embodying the means for forming suitable bearings for an impeller, and a driving shaft therefor, and suitable openings through which fluid may be introduced into the said casing and forced out therefrom.

For effecting the desired pumping of the fluid, as above indicated, and in the practical and improved manner desired, we pro-- vide an impeller which is in the nature of a rotatable cylinder, and the said impeller includes a suction throatway 13 through a hub 14 projecting down into the impeller hub bearing 6. rlhe impeller also includes a bearing portion 15 having suitable bearing, as at 16, on the enlarged bottom portion of the pump casing, as is clearly shown in Figure 1. ln the preferred embodiment of our invention, we desire to construct the impeller in sections, two sections comprising the impeller cylinder proper and a third section including the drive shaft. The main or bottom portion of the impeller, which is in the nature of a circular plate 18, includes one or more (four being shown) impeller blades 17 which are cast integral with said bottom plate 18 and project vertically therefrom and tangentially of the throatway 13 and project, as at 19, into" the annular fluid chamber 20 formed between the enlargements 21, of the bottom plate 18, and 22, of the top or cover plate section 23, of t-he said impeller. lWhen the two sections of the impeller cylinder are secured to each. other, as at 2i, it will be readily apparent therefrom that the parallel plate portions 1S and 23 form therebetween a central fluid chamber, while the enlargements .2l- 22 form therebetween the outer or an' nular fluid chamber into which the blades 17 extend, as at 19, to a point relatively ital distant from the periphery of said fluid chamber 20.

The drive shaft 25 projects vertically through the bearing boss 7 and stufling box l5 and has its connecting flange 26 securely lixed to the impeller, to cause rotation oi the same when power is applied to said shaft, as at 27.

A, number, eight being shown, ol small auxiliary vanes 28, are provided projecting inwardly from the periphery ot the impeller into the annular chamber 20 and the said impeller is also provided with a plurality of ports 29, one thereof being cooperative with cach auxiliary vane 28. By reference to the dra-wings, it will be observed that the impeller is so mounted within the main casing as to provide a relatively large Huid space around the same, and it will also be observed that the ports 29, which are open to communication between the inside ot the impeller body and the said space, are relatively small compared to the area of the suc-tion throatway 13. The combined area of the ports 29 is materially less than the area of the inlet port to the rotor. ln practice, we have found that the best results are obtained, when the pump is designed for a forty foot lift for example, if the combined area of the ports 29 is not over three-fourths of the area ci the inlet port; if the pump is to work on sixty foot head, the combined area of the ports 29 should not be over one-halt of the area of the suction port to give the best results and at greater heads the restriction et the combined area of the ports 29 would be proportionately greater. The greater the head, the smaller must be the ports 29 so that the necessary pressure to oppose the head pressure may be generated within the rotor.

By reason or" the peculiar construction of impeller, the blades, chambers, suction throatway, ports, auxiliary vanes and the .nanner of mounting the same within the main casing, as the column of water is, vby action of the rotating impeller, sucked in tirough the throatway 13, it is out into by the tangential blades 17 and itorced forwardly and outwardly into the annular chamber 20 where it will be caused to baul; against the peripheral wall of the said chamber and approximately held vithin the confines of the impeller until the -rntrifugal Yforce becomes `great enough on the inside of the said impeller to cause the water to l'low through the ports to thereby cause pressure within the outer or casing chamber and the ultimate desired forcing of the fluid out through the di"- charge pipes 11 without any driving action whatever being caused by the outside surface of the impeller'.

lt will be observed the blades 17 extend only part way across the annular chamber 2() so as to leave a relatively wide space between the end of said blade and the periphery of said chamber, thus a free circulation of the fluid is allowed between the said blade ends and the periphery of said annular chamber, thereby allowing the fluid to bank against the said periphery causing a true centrifugal pressure to vbe set un therein. This condition adds weight to the rotating impeller and aids its momentum.

By reason of the peculiar construction of the impeller and the cooperation of the rela.- tively small ports 29 with the chambers of the impeller, and the relatively largek suction throat 13, as above referred to, the fluid is approximately held within the impeller chambers until sufficient pressure is generated therein to properly torce the same out through the relatively small ports 29 into the chamber formed by the space surrounding the impeller. It is therefore readily understood that the fluid is forced out into the casing chamber, and therefrom out through the discharge ports by reason ol the truly centrifugal action, without any drive action whatever by the peripheral surs 'face ol the impeller, and thus, korcing of the fluid by runners, and driving action of blades in forcing the fluid against a closely positioned casing surface, such as is usual in conventional types of centrifugal pumps, is unnecessary in our improved construction ot' centrifugal pump.

lt is to be understood that the blades 17 of our impellerl structure are not a necessity but are used simply as an aid in surrounding the flow of water until maximum speed is obtained in the impeller. This is why vwe allow room 'for the fluid to revolve in an unbroken line within the impeller.

From the foregoing description, taken vin connection with the accompanying drawings, it is thought the complete construction, the operation and advantages of our invention will be readily understood by thoseskilled in the art.

'll/hat we claim is:

1. pump of the class describedcompris ing a casing having openings -tor the entrance and egress of fluid, a rotor journalled within the casing, means for turning the rotor, said. rotor having an axial suction duct and a peripheral annular chamber coi'inected with said duct by a passage ot' less cross sectional area than that of the annular chamber` said rotor having peripheral discharge ports, the combined areas of which are materially less than the area of the suction opening, tor the purposesspecified'.

2. A pump or the class -described'comprising a casing having openings for the entrance and egress of fluid, the entrance opening being axially located, a rotor journalled within the casing and having an axi ally loca-ted inlet duct communicating with the inletl opening of the casing, said rotor including a passage from its inlet opening toward the periphery of the rotor, and an enlarged chamber atthe periphery of' the rotor into which the fluid is passed from said passage, said rotor having peripheral discharge ports, the combined areas of which are materially less than the area ot' the inlet duct of the'rotor, and means by which the motor may be driven.

3. A pump of the class described coniprising a casing having openings for the entrance and egress of fluid, a rotor journa-lled within the casing, means for turning the rotor, said rotor having an axial suction duct and a peripheral annular chamber connected with said duct by a passage of less cross sectional area than that of the annular chamber, said rotor having peripheral discharge ports, the combined areas of which are materially less than the area of the suction opening, and said rotor including peripheral inwardly projecting vane. elements adjacent to the peripheral ports of the rotor, substantially as shown and described.

4. A pump of the class described comprising a casing having openings for the entrance and egress of fluid, the entrance opening being axially located, a rotor journalled within the casing and having an axially located inlet duct communicating with the inlet opening of the casing, said rotor including a passage from its inlet opening toward the periphery of the rotor, an enlarged chamber at the periphery of the rotor into which the fluid is passed from said passage, said rotor having peripheral discharge ports, the combined areas of which are materially less than the area of the inlet duct of the rotor, means by which the motor may be driven, and said rotor including peripheral inwardly projecting vane elements, adjacent to the peripheral ports of the rotor substantially as shown and described.

A pump of the class described comprising a casing having openings to allow the egress of fluid, and having an inlet duct axially located, a rotor mo-unted within the casing and having an axially located inlet duct set into the inlet duct of the casing and having bearing thereon, a drive shaft t'or the rotor projected through the casing said casing having a. bearing portion lor the drive; shaft, said rotor also including a pair of central parallel plate portions and peripheral annular concavo convex portions, the latter constituting an annular enlarged chamber into which the fluid is discharged from between said central plate portions, blades mounted between said central plate portions and terminating short of the periphery of the rotor to leave an uninterrupted annular flow passage in `the rotor for the fluid, said rotor having peripheral outlet ports, the combined area of which is less than the area of the inlet duct of' the rotor, for the purposes specilied,

6. A pump of the class described comprising a casing having openings to allow the egress of fluid, and having an inlet duct axially located, a rotor mounted within the casing and having an axially located inlet duct set into the inlet duct of the casing and having a bearing thereon, al drive shaft for the rotor projected through the casing, said casing having a bearing portion for the drive shaft, said rotor also including a pair of central parallel plate portions and peripheral annular concavo convex portions, the latter constituting an annular enlarged chamber into which the fluid is discharged from between said central plate portions, blades mounted between said central plates portions and terminating short of the periphery of the rotor to leave an uninterrupted annular flow passage in the rotor for the fluid, said rotor having peripheral outlet ports the combined area of which is less than the area of the inlet duct of the rotor, said rotor having relatively short auxiliary vanes projected inwardly from the periphery thereof' and located adjacent to the outlet ports of the rotor.

7. A pump of the class vdescribed comprising a casing having an outlet port and an inlet port, said casing having rotor bearings, a rotor journalled in said bearings and comprising a lower section and an upper section with means to secure said sections together, each of said sections comprising parallel central disk portions, and peripheral concavo convex portions, the latter forming an enlarged annular ductlike chamber in which the water can circulate in a path around the axis of the rotor, the lower section havinO` a central inlet port and a plurality of peripheral outlet ports, the combined area oi' said outlet ports being less than the area of said inlet port, said disl -lilre portions of said rotor being spaced apart to constitute a passage from the inlet port to the annular chamber ofthe rotor.

S. A pump of the class described comprising a casing having an outlet port and an inlet port, said casing having rotor bearings, a rotor journalled in said bearings and comprising a lower section and an upper section with means to secure said sections together, each of said sections comprising parallel central disk portions and peripheral concave convex portions, the latter forming an enlarged duct-like chamber in which the Water can circulate in a path around the axis oi" the rotor, the lower section having a cent-ral inlet port and aV f" plurality of peripheral out-let ports, the

combined area of said outlet ports being less than the area of said inlet ports, Said disklile portions of Said rotor being spaced apart to constitute a passage from the inlet port to the annular chamber of the rotor, 10

and blades andL auxiliary vanes Within the rotor for the wpurposes specied, said blades beingloeatedV between Said disk-like portions and sa'id auxiliary vanes being located at the periphery of the rotor adjacent to the 15 outlet ports of the same.

TAD DANFO'RD. ALBION P. CURTIS. 

